Protective structure

ABSTRACT

A surface-covering protective structure. A thermal insulation layer has a basic wall thickness, fastening elements and a support arrangement integral with and projecting from the basic wall thickness of the thermal insulation layer. The support arrangement includes a plurality of supporting feet each comprising a supporting surface being operable to engage a protected surface that the protective structure is arranged on. The support arrangement is operable to physically separate the basic wall thickness of the thermal insulation layer from the protected surface. The fastening elements are operable to couple adjacent protective structures together. The protective structure, including the basic insulation layer, the fastening elements, and the support arrangement, includes thermally insulating plastic material operable to thermally insulate the protected surface.

REFERENCE TO RELATED APPLICATION

This Application is a 371 of PCT/FI97/00545, filed Sep. 9, 1997.

The invention relates to a protective structure, such as a protectingplate or element, that is meant particularly for covering of ground toprotect and/or coat the same and/or for a like purpose and, into whichthere has been arranged at least a thermal insulation and a supportarrangement for supporting of the same onto the ground.

For the purpose above, particularly for covering a field of grass ore.g. of ice, it is previously known to use most heterogeneousarrangements. For example covering elements being sold nowadays by thename TERRAPLAS represent particularly more developed solutions, that aremade of plastics by injection moulding. To minimize mass of the coveringelement in question, it has been produced as a perforated structure in away, that not any actual thermal insulation effect may be achieved bythe type of covering element. Correspondingly the support arrangementsto support the covering elements against the ground must furthermore beattached to the covering elements by means of totally separate auxiliarydevices and work stages. In addition to this locking arrangementsconnecting the covering elements to each other must be attachedseparately as well, so that a uniform covering may be achieved by thetype of covering elements. The “perforated” structure of the type ofcovering element above does not either enable exploitation of a socalled green house phenomen particularly in connection with a grassfield.

The perforated structure of the covering element in question isnaturally advantageous with a view to the breathing of the ground, butthe perforation causes in addition to those thermal insulation problemssuch disadvantage as well, that garbage may get collected between thecovering and the ground, which naturally eliminates good points of thecovering element in question in this respect.

On the other hand it is previously known to use e.g. styrox particularlyfor covering of ice fields, that has been surrounded by both sides ofthe same by plywood plate. This type of solution is naturally notapplicable as such to be installed particularly on a grass field, incase not totally separate foot structures are being used to raise thecovering structure apart from the ground. On the other hand when beingused in connection with an ice field, such problem of this type ofsolution has been found, that the plywood plates tend to freeze to theice, that is why loosening of the same is laborious. In addition to thatthe type of constructions are very heavy, that is why storing as well asuse of the same in actual coating is disproportionately difficult.

On the other hand application document DE 41 12 757 discloses a coveringelement, in which there has been arranged a supporting arrangement, thatcomprises a platform structure under the same to achieve e.g. an airspace between the covering element and the ground under the same. Inthis solution the actual platform structure has been formed, however,from a separate material layer, that has been attached fixedly e.g. bymeans of a glue layer to the actual frame structure, to the oppositesurface of which there has been attached e.g. by a glue layer a surfacelayer. In the solution in question there has been exploited furthermorerubber based material, that is why not any particular thermal isolationeffect may be achieved with the covering element in question. Becauseproduction of the solution in question requires several work stages,this type of covering elements get disproportionately expensive.Furthermore in patent U.S. Pat. No. 4,291,851 there has been representeda structure solution, that is not meant particularly as a coveringelement to be applicable for temporary protecting of ground, but insteadas a uniform and constant internal casing of an aeroplane, that is whyit is not in any way obvious to exploit the construction in question ofthe same for the purpose described herewith. Furthermore in patent U.S.Pat. No. 3,870,587 there has been shown differing panels, theconstructions of which are very traditional and which are applicablee.g. for covering of ice field, but the compositions of which correspondmainly the prior art technics described in the beginning, that is whythey are particularly expensive to produce. This is why they do not haveeither any kind of price competition ability, when keeping in mindmodern demands.

It is the aim of the protective structure according to this invention toachieve a decisive improvement in the problems presented above and thusto raise substantially the level of knowledge in the field. To achievethis aim, the protective structure according to the invention isprimarily characterized in, that the thermal insulation of a protectivestructure, that is meant particularly for temporary protecting of afield of grass and/or of ice comprises at least one, preferably plasticbased, such as cell, cellular, foam plastic structured or a like thermalinsulation layer, whereby a support arrangement, that is formed of thebottom surface of the same, comprises a platform structure projectingfrom the basic wall thickness of the thermal insulation layer,particularly to achieve an air space between the protective structureand the ground under the same.

As the most important advantages of the protective structure accordingto the invention may be mentioned simplicity and technical workabilityof the construction, production and use of the same. The structureaccording to the invention enables first of all a very good thermalinsulation ability thanks to that, that in addition to the thermalinsulation layer this influence is being effected by means of the airspace between the protective structure and the ground. Furthermore thefeet being arranged as a built-in platform structure directly to thebottom surface of the thermal insulation layer prevent first of all“burning” of the grass that is left under the protective structure, andon the other hand freezing of the type of protective structure inquestion onto the ice. The protective structure according to theinvention is furthermore significantly lighter than the correspondingnowadays solutions, that is why it is idealistic both with a view touse, installation as well as storing. The protective structure accordingto the invention does not require either support arrangements to beattached to the same by separate work stages or other stiffeningstructures, but instead all the above may be produced totally built-induring production of the protective structure. The protective structureaccording to the invention is, as explained above, advantageous in thatrespect as well, that alike construction may be exploited in principleboth for covering of fields of ice as well as of grass.

Advantageous embodiments of the protective structure according to theinvention are represented in the dependent claims related to the same.

In the following description, the invention is illustrated in detailwith reference to the appended drawings. In the drawings,

FIGS. 1a and 1 b show a principle of the thermal insulation layerbelonging to the protective structure according to the invention as adetail from a point having a basic wall thickness,

FIGS. 2a and 2 b show some advantageous protective structures accordingto the invention particularly for covering of a field of grass (2 a) andof ice (2 b),

FIGS. 3a and 3 b show an advantageous form locking arrangement betweenthe frame parts as a perspective view (3 a) as well as a view seen fromabove and a side view (3 b),

FIGS. 4a and 4 b show placement of fastening means being carried outdifferently to the protective structures as a view seen from above (4 a)and one advantageous joint principle between the protective structuresas alternative side views (4 b), and

FIG. 5 show some advantageous simplified fastening arrangements placedat the outer edges of the protective structures.

The invention relates to a protective structure, such as a protectingplate or element, that is meant particularly for covering of ground toprotect and/or coat the same and/or for a like purpose. Into theprotective structure there has been arranged at least a thermalinsulation 1 and a support arrangement for supporting of the same ontothe ground. The thermal insulation 1 of a protective structure, that ismeant particularly for temporary protecting of a field of grass and/orof ice comprises at least one, preferably plastic based, such as cell,cellular, foam plastic structured or a like thermal insulation layer 1′,whereby a support arrangement 1 a, that is formed of the bottom surfaceof the same, comprises a platform structure projecting from the basicwall thickness s of the thermal insulation layer 1′, particularly toachieve an air space between the protective structure and the groundunder the same.

As an advantageous embodiment particularly with reference to FIG. 1b thethermal insulation layer 1′ of the protective structure has beenarranged coated preferably on both opposite sides of the same,preferably by spraying with thermoset type or a like coating material 2,particularly to achieve a damp stop to the boundary surfaces of thethermal insulation layer 1′ or for example for strenghtening of theprotective structure. In this connection it is naturally possible to useother type of coating materials as well, when exploiting suitablecoating technics. The type of thermoset plastic materials as describedabove have actually such advantage, that they may be arranged by verysimple work stages by spraying to the surface of the thermal insulationlayer 1′. In this connection as the spraying method furthermore e.g.electrostatic coating or high pressure coating etc. may be furthermoreexploited.

Furthermore with reference particularly to the advantageous embodimentshown in FIG. 1a, to the top surface of the thermal insulation layer 1′there has been attached, preferably by lamination with a coatingmaterial 2 or correspondingly a stiffening structure 3, such as awooden, metal, plastic sheet, plate and/or a like. Furthermore as anadvantageous embodiment the stiffening structure 3 has been arrangedfinished preferably during manufacturing of the protective structure, byarranging the top surface of the same coated with a damp proof, surfacepatterned, coloured and/or like coating 2′.

The protective structure shown in FIG. 2a is meant particularly forcovering of a field of grass or like, whereby, to achieve an essentiallyuniform coating, it comprises preferably fastening means, beingdescribed in a greater detail in the text later on, to attach one orseveral adjacent corresponding protective structures to the same.

In the protective structure shown in FIG. 2a, the basic wall thickness sof the thermal insulation layer 1′, that essentially acts as the framepart of the protective structure, is 30-80 mm. With a view to grassfields by tests in practice the wall thickness has been found to beadvantageously 40 mm. With further reference to the figure in questionfor formation of the support arrangement 1 a to the bottom surface ofthe frame part there has been arranged supporting feet or like, theheight h1 of which is 20-80 mm, preferably 50 mm. In this connection itis furthermore, when needed, possible to arrange the protectivestructure to breathe by means of holes 4 passing through the same,preferably essentially vertically.

The aerobic air space belonging to the type of construction above givesthe grass first of all a possibility to breathe, in addition to which itenables partial air flow between the ground and the protectivestructure. The air space in question gives furthermore room for growingof the grass, in which connection it has been found in practice, that ashort period of use (1-3days) of the protective structure according tothe invention accelarates growth of the grass, because advantageousgrowth circumstances are formed under the plate, that is very highhumidity and nitrogen contents. By tests in practice it has beennotified furthermore, that the grass is not allowed to get dry, thatmeans to “burn” under the plate. In addition to that, thanks to thebottom structure as described above, only about 5-20% of the grass underthe plate remains under mechanical stress.

Furthermore with reference to the advantageous embodiment shown in FIG.2b, that is meant particularly for covering of a field of ice or a likeground, the basic wall thickness s of the thermal insulation layer 1′,that acts essentially as the frame part of the protective structure, is20-60 mm, preferably for example 22 mm. Tests in practice have shownthat it may be even thinner particularly with a view to thermalinsulation influence. Furthermore as an advantageous embodiment in thesolution in question the height h2 of the supporting feet existing atthe bottom surface of the same is 2-10 mm, whereby the height of feet of3 mm has been found advantageous in practice.

As an advantage of the construction presented above it has been found,that it keeps the ice surface cool, but does not however freeze onto thesurface of ice.

To achieve the effects described above it has been found furthermore inpractice for example, that the number of support feet in the thermalinsulation layer 1′ is advantageously 25 pcs/m², the diameter D of whichis preferably about 120 mm.

Furthermore as an advantageous embodiment, the frame part of thecovering plate or element that means particularly the thermal insulationlayer 1′ has been manufactured to its final shape by the appearance ofthe same by cast moulding, foaming or compression moulding and/orcorrespondingly.

Furthermore as an advantageous embodiment, the fastening means actingfor example by quick locking principle are arranged to the protectivestructure by process techniques, such as by casting, machining and/orcorrespondingly, as a part entirety belonging to the same essentiallybuilt-in.

Furthermore as an advantageous embodiment, each protective structure isformed of two or more frame parts A, that are, to achieve a uniformprotective structure, coupled by means of a form locking arrangement 5,that is placed at the joint sides L of the same to be coupled to eachother, and by means of a stiffening structure 3, such as by plate ofABS, PVC, PP plastics, electro-galvanized steel, plywood and/or a like,that is arranged in connection with the same, such as on top of thesame, by lamination, thermal forming, gluing and/or correspondingly.

As an advantageous embodiment particularly with reference to FIGS. 3aand 3 b the form locking arrangement 5 has been formed by means of formlocking projections 5 a′ and locking grooves 5 a″, that are placed atcorresponding points to one or several joint sides L of each frame partA and placed alternatively to the top and bottom edges of the same, thatare aimed to prevent mutual movement of the frame parts A connected toeach other preferably in three directions x, y, z perpendicular to eachother.

As an advantageous embodiment the size of the protective structure is500 mm×500 mm−1500 mm×3000 mm, preferably for example 1500 mm×1500 mm,wherein it is formed preferably of three frame parts A, the size ofwhich is 500 mm×1500 mm. The measures mentioned above are advantageousfirst of all with a view to installation of the covering formed of theprotective structures, because the protective structures may betransported to the installation site as big as possible. With a view tonowadays manufacturing techniques it has been found, however, moreadvantageous to produce with one mold frame parts, the size of which is1500 mm×500 mm at the most, in which case the invention enablesproduction of protective structure having an adequate size and that canbe simply enough installed.

Furthermore as an advantageous embodiment, the thermal insulation 1 ofthe protective structure consists of EPS-material, such as expandedcellpolystyrene foam, styrox or like, XPS-material, such as extrudedpolystyrene foam, EPP-material, such as expanded polyprophylene foam,extruded polyethylene foam or extruded PVC structural foam sheet.

Furthermore as an advantageous embodiment particularly with reference toFIG. 4b the outer edge R of the protective structure is arrangedchamfered and/or profiled, particularly to minimize flowing of air, heatconduction and/or like through the joints between the protectivestructures. The chamferings or profilings in question may be placed toonly those parts of the outer edges, that remain free for the part ofthe fastening means or as well essentially at the point of the same.

Furthermore with reference particularly to the alternative solutionsshown in FIG. 5, the fastening means 6 between the protective structuresmay comprise e.g. female and/or male couplers 6 a, 6 b e.g. at eachouter edge R of the protective structure. In this connection it ispossible to exploit thus a hook like locking 6 a′, 6 b′ shown in theuppermost figure, a groove locking 6 a″, 6 b″ shown in the followingfigure or a pin locking 6 a 1, 6 b 1 existing at the same level, asbeing exploited in the figure below the above, or furthermore a pinlocking 6 a 2, 6 b 2 being represented in the lowermost figure, in whichthe pins exist in different levels. Furthermore with reference toalternative protective structure solutions shown in FIG. 4a the type offastening arrangement 6 as described above may be placed in the surfacestructure e.g. in three different ways. In the figure on the left sidethe male and female joints are placed at the opposite outer edges R. Inthe middle figure the male and female joints are placed at adjacentedges and furthermore in the figure on the right the male and femaleparts have been placed adjacently at each edge of the surface structure.As explained above, the female and male couplers acting as fasteningarrangement 6 may extend to the whole length of the side or they mayconsist of one or several shorter part entireties.

Furthermore as an advantageous embodiment particularly to FIG. 2b, anauxiliary support arrangement, such as one or several stiffening bars,ribs, profiles, frames and/or like have been arranged between thestiffening structure 3 and the thermal insulation layer 1′. Theauxiliary support arrangement 7 in question may be carried out so, thatit has been arranged totally built-in to the thermal insulation layer 1′during manufacturing of the same. The auxiliary support arrangement inquestion may be produced advantageously e.g. of wood, metal, plastic,coal fiber etc.

It is obvious, that the invention is not limited to the embodimentspresented or described above, but it can be modified within the basicidea even to a great extent. In this connection it is naturally possibleto equip the protective structure according to the invention moreabundantly by exploiting e.g. according to traditional practice separatesupport arrangements or a totally separate coating, such as awall-to-wall carpet, in connection with thermally insulative protectiveelements, that are coated only by the opposite surfaces of the same. Itis naturally furthermore clear, that protective structures asrepresented above may be coupled to each other with most heterogeneousfastening arrangements. In addition to that the protective structuresmay be attached to each other in very many ways, in which case thefastening mechanism may be produced as described above integrally duringproduction of the plate and that is a rigid arrangement and formed ofthe frame/surface material of the protective material. In addition tothis rigid arrangements may be exploited in that way as well, thatduring manufacturing of the actual frame components, there has beenexploited e.g. wooden, metal, metal structured or the like inserts. Theinserts in question may be installed later on as well to theframe/surface plate.

What is claimed is:
 1. A surface-covering protective structure,comprising: a thermal insulation layer having a basic wall thickness,fastening elements and a support arrangement integral with andprojecting from the basic wall thickness of the thermal insulationlayer, the support arrangement comprising a plurality of supporting feeteach comprising a supporting surface being operable to engage aprotected surface that the protective structure is arranged on, thesupport arrangement being operable to physically separate the basic wallthickness of the thermal insulation layer from the protected surface,the fastening elements being operable to couple adjacent protectivestructures together, whereby the protective structure including thebasic insulation layer, the fastening elements, and the supportarrangement comprises thermally insulating plastic material operable tothermally insulate the protected surface.
 2. The protective structureaccording to claim 1, wherein the thermally insulating plastic materialcomprises at least one of cell, cellular, structured foam plastic. 3.The protective structure according to claim 1, further comprising: acoating on at least one surface of thermal insulation layer.
 4. Theprotective structure according to claim 3, wherein the coating providesat least one of a moisture barrier and a strenghtening structure.
 5. Theprotective structure according to claim 3, wherein the coating comprisesa thermoset material.
 6. The protective structure according to claim 1,further comprising: a stiffening structure attached to a top surface ofthe thermal insulation layer.
 7. The protective structure according toclaim 6, wherein the stiffening structure laminated on the thermalinsulation layer.
 8. The protective structure according to claim 6,wherein the stiffening structure comprises at least one of wood, metal,and plastic.
 9. The protective structure according to claim 6, furthercomprising: a coating on a top surface of the stiffening structure. 10.The protective structure according to claim 9, wherein the coatingcomprises at least one of a moisture proof coating, a surface patternedcoating, and a colored coating.
 11. The protective structure accordingto claim 1, wherein the thermal insulation layer has a basic wallthickness of about 30 mm to about 80 mm.
 12. The protective structureaccording to claim 1, wherein the thermal insulation layer has a basicwall thickness of about 40 mm.
 13. The protective structure according toclaim 1, wherein the thermal insulation layer has a basic wall thicknessof about 20 mm to about 60 mm.
 14. The protective structure according toclaim 1, wherein the thermal insulation layer has a basic wall thicknessof about 22 mm.
 15. The protective structure according to claim 1,wherein the support arrangement comprises supporting feet.
 16. Theprotective structure according to claim 15, wherein the supportarrangement a thickness of about 20 mm to about 80 mm.
 17. Theprotective structure according to claim 15, wherein the supportarrangement has a thickness of about 50 mm.
 18. The protective structureaccording to claim 15, wherein the support arrangement has a thicknessof about 2 mm to about 10 mm.
 19. The protective structure according toclaim 15, wherein the support arrangement a thickness of about 3 mm. 20.The protective structure according to claim 1, further comprising: aplurality of breathing holes through the thermal insulation layer. 21.The protective structure according to claim 15, wherein the supportarrangement comprises about 25 supporting feet per square meter.
 22. Theprotective structure according to claim 15, wherein the supporting feethave a diameter of about 120 mm.
 23. The protective structure accordingto claim 1, wherein the thermal insulation layer is manufactured to afinal shape by at least one of cast molding, foaming, and compressionmolding.
 24. The protective structure according to claim 1, wherein theprotective structure comprises at least two frame parts, each frame partcomprising the thermal insulation layer, the protective structurefurther comprising: a locking arrangement arranged on joint sides of theat least two frame parts and operable to couple the fame pans together,and a stiffening structure operable to couple the fame parts together.25. The protective structure according to claim 24, wherein thestiffening structure comprises a plate comprising at least one of ABS,PVC, PP plastics, electro-galvanized steel, and plywood, the plate isarranged on top of the frame parts and operably connected to the framepans by lamination, thermal forming, or gluing.
 26. The protectivestructure according to claim 24, wherein the protective structure has asize of about 500 mm by 500 mm to about 1500 mm to about 3000 mm. 27.The protective structure according to claim 24, wherein the protectivestructure has a size of about 1500 mm by 1500 mm.
 28. The protectivestructure according to claim 2, wherein the protective structurecomprises three frame parts each have a size of about 500 mm by about1500 mm.
 29. The protective structure according to claim 2, wherein thethermally insulating plastic material comprises at least one ofEPS-material, XPS-material, EPP-material, extruded polyethylene foam,and extruded PVC structural foam sheet.
 30. The protective structureaccording to claim 29, wherein the EPS-material comprises at least oneof expanded polystyrene foam and styrox, the XPS material comprisesextruded polystyrene foam, and The EPP material comprises expandedpolyprophylene foam.
 31. The protective structure according to claim 1,wherein an outer edge of the protective structure is at least one ofchamfered and profiled to minimize at least one of air flow and heatconduction through joints between adjacent protective structures. 32.The protective structure according to claim 1, further comprising: anauxiliary support arrangement.
 33. The protective structure according toclaim 32, wherein the auxiliary support arrangement comprises at leastone stiffening bar, rib, profile, and frame.
 34. The protectivestructure according to claim 32, wherein the auxiliary supportarrangement comprises wood, metal, plastic, or carbon fiber.
 35. Theprotective structure according to claim 32, wherein the auxiliarysupport arrangement is arranged within the basic wall thickness of thethermal insulation layer.
 36. The protective structure according toclaim 1, further comprising: an auxiliary support arrangement arrangedbetween the stiffening structure and the thermal insulation layer. 37.The protective structure according to claim 1, wherein the fasteningelements comprise male couples extending from outer edges of the thermalinsulation layers and complementary shaped female couplers extendinginto outer edges of the thermal insulation layers.
 38. The protectivestructure according to claim 37, wherein the fastening elements extendalong at least a portion of each edge of each thermal insulation layer.